Process of refining and desilverizing lead.



G. P. HULST.

PROCESS OF REFINING AND DESILVERIZING LEAD.

APPLIOATION TILED 00'1'.28, 1910.

1,001,525, Patented Aug. 22, 1911.

Q 3 B ETBSHEET 1.

W ATTORNEYS COLUMIIIA PLANOGRAPII 60.. WASHINGTON. By C.

G. P. HULST. PROCESS OF REFINING AND DBSILVERIZING LEAD.

APPLICATION TILED OUT. 28, 1910.

1,001,525. Patented Aug. 22, 1911.

3 BEEETBBHEET 2.

' ATTORNEYS G. P. HULST.

PROCESS OF REPINING AND DESILVERIZING LEAD.

APPLICATION TILED OCT. 28, 1910.

Patented Aug. 22, 1911.

3 BHBETB8HIIET 3.

INVENTOR eorye Pflmlsl BY WITNESSES ATTORNEYS GEORGE HULST. O1? OMAHA, NEBRASKA.

PROCESS OF BEFINING AND IDESILVERIZING LEAD.

Specification of Letters Patent.

I at-outed Aug. 22, 1911.

Application filed October 28, 1910. Serial No. 589.589.

To all whom it may concern:

Be it known that l, (lnonon l lli iis'r, a citizen of the United States, and a resident of Omaha, in the county of Douglas and State of Nebraska, have invented a new and Improved Process of ltelining and l)esilverr/ang liead, oil: which the Following is a toll, clear, and exact descrrptum.

The invention relates to relining and desilverizing by the crystallivatimi process, and

its object is to provide a new and improved method for relining and desilverizing lead bullion and impure lead, and whereby the number of erystallizing operations is reduced to a minimum tor the proper prmluction of high grade bullion or metal running live hundred to six hundred ounces silver and a market lead.

The invention consists in a method where by the crystals in a crystallizing kettle are 1 subjected to pressure tosqneeze out the nn- 2 Figure l is a side elevation of a series of six kettles and the ltramework and overhead crane used in lifting the kettles and the press; Fig. 2 is an enlarged sectional side elevation oi one of the kettles and the press in position thereon; Big. 3 is a side elevation of the upper end of one of the kettles and the lower ends oil the standards ot the press tastened in place on the kettle; and Fig. 4

is an enlarged sectional side elevation ot one so that steam can be passed into the molten ot' the kettles in which a fluid under pressure is used for squeezing out the uncrystah lined .liqnid.

The crystallization processes heretofore used are leased on the tact that lead or lead bullion carrying silver, gold, and other impurities, such as bismuth, copper, arsenic, zine, antimony, and the like, and cooled down to nearly a solidifying point and stirred by hand or meehanitailly by suitable devices in a crystallizing kettle, form crystals ot' lead which are treer from silver and other inrpurities, such as above mentioned, than the liquid which permeates the entire mass of l m n sh y crystals.

In the crystallization process referred to the nncrystallized liquid is strained otl by gravity through one or more tap holes in the bottom oi the crystallizing kettle, and it takes usually about twelve crystallization operations to produce market lead at one end and live hundred ounces per ton metals tor cupeling at the other end. The crystals are granular and spongy, and a quantity of u|u-r \"stal|ized lead or liquid is held in suspension or permeates the whole mass ol crystals. and by gravity not all ol this uncrystallized lead is strained out in the processes mentioned and heretotore used. \Vith my invention. presently to be described in detail, the crystals are subjected to pressure so as to squeeze out the unerystallizcil lead or liquid trom the crystals to render the latter drier, that is, treer from the liquid lead, which latter is higher in silver and other immnities than the crystals. With my improvement the number o'l. kettles and the number o'l crystalliningg (nierations are reduced to about; six. that is, one-halt" ol that hereto'l'ore re(|uired, and hence a direct output of market lead can be obtained in a comparatively short time.

A. series o'l kettles A, A, A A", A and A. are placed apart and arranged preterably as shown in Fig. l, and each kettle is nected by a trough C with another kettle,

as indicated in Fig. 11,.

into each ot the kettles opens at the bottom a steam supply pipe D directly under a ballle plate l l, as plainly shown in Fig. 2-,

lead with a view to cool the same and to cause agitation thereol tor the ilormation ot the crystals, as is well known in the crystallization process. l lach ot the steam sup ply pipes l) is provided with a valve l) for controlling the steam passing into the corresponding kettle, and each steam supply pipe l) has a sliding connection with a tixed pipe I) (see l ig. l), conm-cted with a boiler or other suitable source oi steam supply.

llnder each kettle is arranged a burner F having a pipe I provided with a valve F, the said pipe I ha ving a sliding connection with a supply pipe l connected with a suitable source of gas supply. so that the kettle may be heated whenever it is desired to do so.

The top of each kettle A, A, A A A and A is provided with sets of lugs G, on which are removably fastened by keys G the lower ends of standards H of a press H, having a cylinder H mounted. to slide up and down on the standards H. In the cylinder H is arranged a piston I attached to rods 1 extending upwardly and secured to a top plate J carried by the standards H. On the lower end of the cylinder H is secured a presser plateK adapted to pass into the corresponding kettle with which the press H is connected at the time, so as to subject the crystals therein to pressure with a view to squeeze out of the crystals the uncrystallized liquid, as hereinafter more fully explained. A pipe L connected with an elastic fluid pressure supply opens into the lower end of the cylinder H and the pipe L is provided with a three way valve L, which when turned one way allows the fluid pressure to pass into the lower end of the cylinder H to force the latter clownward, thus moving the presser plate K into the corresponding kettle for the purpose mentioned. hen the valve L is turned in the opposite direction it serves as an exhaust valve for the interior of the cylinder H A pipe N having a three way valve l similar to the valve L in the pipe L and also connected with a pressure supply opens into the upper end of the cylinder H to force the cylinder H upward after the pressing operation is completed. It will be understood that when one of the valves L or N is turned to its exhaust position the other valve is opened to admit fluid pressure into the cylinder.

The presser plate K is provided with perforations K, and at one side with a depending channel K registering with a pipe K fastened to the wall of the kettle (see Fig. 2), and provided with a valve K Now when the presser plate K moves down ward in a kettle, the liquid passes up through the perforations K onto the up per face of the presser plate K, to then run to the channel K and out of the same by way of the now open pipe K into a ladle or into another kettle, as hereinafter more fully explained.

The top plate J of the press H is pro vided with a chain or loop 0 adapted to be connected with one of the hooks P of an overhead traveling crane P of any improved construction, to permit of raising and low.

ering the press H and to allow of bringing the press H into position on any one of the kettles A, A, A A A and A It is understood that when the press H hasbeen lowered onto the top of any one of the kettles, it is readily fastened to the lugs Gr of this particular kettle by the keys Gr, so as to hold the press H temporarily in place on the corresponding kettle. After the pressing operation is finished the keys G are removed and the press H is lifted to disconnect it from the kettle and to allow of connecting the press with another kettle in which the next pressing operation is to take place.

The kettles A, A A A A3 and A are mounted to slide up and down in suitable guideways R (see Fig. 1) and each kettle is provided at its upper end with outwardly extending lugs S. Disposed above the series of kettles is an overhead crane P provided with hooks P arranged to engage a link T of a cross head T, the latter is provided with a series of depending links T adapted to engage the lugs S in order to raise the kettles into their upper positions. ll will be understood that as many of these lifting devices, similar to the ones just described, may be used as are necessary.

Now, by the arrangement described, any one of the kettles can be connected by the lifting device described with a hook P of the overhead crane to raise this kettle into a discharging position, as indicated in Fig. l, in which the kettles A, A and A are shown raised and connected by the troughs C with the kettles A, A and A appearing in lowermost position. The raised kettles are supported in the raised position by suitable legs or props R, which are set under the kettles after they are raised.

The operation is as follows: When the apparatus is in use, alternate kettles are full while others are empty, the molten bullion assaying in the several kettles when full as follows: The liquid high grade metal taken from the kettle A by way of the pipe K assays 500 ounces Ag. per ton, the metal in the several kettles A, A, A A A and A assaying per ton, respectively, 300 oz. Ag., 180 oz. Ag, oz. Ag., 25 oz. Ag., 5 oz. Ag. and 1 oz. Ag, while the market lead from melted crystals in the kettle A assays oz. Ag. per ton. Presuming that the kettles A, A and A are full of molten bullion of the grades above mentioned, while the kettles A and A are empty and the kettle A is one-eighth full from a previous operation, only tapping out siX-eighths (3) of market lead, so that the kettle A fil s from the kettle A at the next operation and melted crystals run down. Presuming further that the apparatus is running seveneighths crystals, then the kettles A, A and A are first allowed to cool down, the heat from the burners F being turned off, and then steam is admitted by way of the pipes D to form seven-eighths crystals. This process can be hastened by supplying water to the top of the lead through a pipe, the steam being temporarily shut off for the time. After the crystals are formed, the steam is shut off by closing the valves D". A slow fire is now started under the kettles A, A? and A by the use of the burners ll, and the said kettles are then raised by the use of the lifting device (T, 'l", T) and overhead crane l. to the position shown in Fig. 1, and then the presses It are connected with the said kettles and set in action. The high grade metal press-ed out in the kettle A passed by way of its pipe K into a ladle carried by the overhead crane I to cupels, and the liquid pressed out in the kettle A is passed by way of its pipe 1i and a trough K into the kettle A, while the pressed out liquid from the kettle A, is passed by way of its pipe K and a trough K into the kettle A. After one-eighth t liquid has been pressed out of the kettles A, A? and A more heat is turned on by the use of the burners F, to melt down the pressed crystals. The presses ll are now detaehed from the kettles A, A? and A', and removed by the use of the overhead crane 1 As soon as the crystals are melted down in the kettles A, A? and A", the valves in the outlets C for the said kettles are opened and the molten crystals from the kettle A are run into the kettle A, those trom the kettle A are run into the kettle A. and those from the kettle A are run into the kettle A, by way of the troughs C. The kettles A, 2 and A are now empty and are lowered to the level of the other kettles A, A and A, which are now 'tull. It is understood that during the erystallizing of the lead by means of the steam and the subsequent melting down of the crystals, and the transfer of the resulting liquid from one kettle to another various impurities are Formed, and these drosses are skimmed olt' clean from the full kettles just before beginning the crystallization. The above-described operation relating to the kettles A, A? and A is now repeated relative to the kettles A, A and A, that is, dry steam is turned on for the kettles A, and A, to crystallize their contents to seven-eighths (i), and then a slow fire is started under the said kettles A, A by the corresponding burners F, after which the kettles A, A A. are raised by the use of the overhead e 'ane P and supported by the legs R in the raised position as before explained. The presses H are now applied to the raised kettles A, A A, and actuated to press out the liquid and conduct the same by way of the corresponding pipes K and troughs to the nonraised kettles A, A and A", that is, the liquid is run from kettle A into kettle A, from kettle A" into kettle A? and from kettle'A into kettle, A3. The burners l for the kettles A, A and A are now turned on Full, to melt down the crystals contained in the said kettles, after which the presses ll are removed. The melted crystals from kettle A are now run into kettle A and those from kettle A are run into kettle A by way of the outlets (l and troughs C. The kettles A, A, and A are now lowered and six-eighths (ii) market lcad run oil from the kettle A into suitable molds. The other one-eighth crystals are lett in the kettle A so that the kettle A" is again tilled with melted crystals at the next operation from the kettle A", as previously explained. it will be noted that the kettle A. is one-eighth (1) tall while the kettles A A are completely filled and crystals are in :ach kettle and high grade metal and market lead has been run oli. Seveireighths bullion of respective grade is now charged into kettle A, so that the kettles A, A and A will be full after the metal in the ket tles A A' has been crystallized and the pressed out liquids l'rom kettles A and A tapped into kettles A, A and A" from A and A", and melted crystals tapped lrom kettles AF and A into kettles A and A. respectively. Charging with bullion is done from time to time as needed, but the bullion ehar e ;ed into a kettle must he oi the respective grade, that is, the same number of ounces of silver per ton, in order to keep the plant in tall operation.

From the foregoing it will be seen that by the arnmgcmcnt described it requires only six (mcrations to n'oducc market lead at one end and live lumdred ounces per ton enriched metal at the other end. As is well known, with the processes now in use it rcquires the cmplovmcnt of about twelve kettlcs and a corresponding number of crystallixation operations to make market lead and enriched metal as above described.

It is understoml that l do not limit myself to running the bullion at the scvcn-cighths proportion above explained, as the same process may be carried out on any traction.

instead of using mechanical means (plunger K) for pressing out the uncrystallizcd liquid, use may be made oi fluid pressure for the same purpose. in the :qiparatus shown in Fig. the kettle A is provided with a cover A carrying a valved pipe U connected with a fluid pressure supply such as steam, couqircssed air or the like, and the kettle is further provided with valved outlets (F and K oi which the outlet K is tor the discharge oi the uncrystallirced liquid squeezed out of the crystals by the fluid pressure on top of the mass in the kettle A. A strainer K is arranged in the kettle A ovcr the entrance to the pipe K to prevent the crystals "From passing out of the kettle by way oi the pipe K it being uiulcrstoml that the crystals are discharged from the kettle by way of the outlet (l Although l. have shown one particular ay of agitating the molten metal in the kettles 'l'or etl'ecting crystallization, it is evident that other means may be employed for this purpose, and it is also understood that I do not limit myself to the particular construction of the press H employed, as other mechanical or fluid pressure may be used for carrying on the pressing operation.

Having thus described my invention, I claim as new and desire to secure by Letters Patent:

1. The herein described process of refining and desilyerizing impure lead, Which consists in melting the impure lead bullion, crystallizing a portion of the lead from the molten bullion, separating the molten impure lead from the crystallized lead by pressure applied to the crystals, and conducting the impure lead away from the crystals.

2. The herein described process of refining and desilverizing impure lead bullion, which consists in melting the impure lead bullion, crystallizing a portion of the lead from the molten bullion by cooling and aginame to this specification in the presence of 35 two subscribing Witnesses.

GEORGE P. HULST. Witnesses T1 1130. G. Hosrnn, PHILIP D. ROLLHAUS.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

